Automatic merge from submit-queue (batch tested with PRs 41349, 41532, 41256, 41587, 41657)
Lint fixes for the master and worker Python code.
**What this PR does / why we need it**: lint fixes for the python code.
**Which issue this PR fixes** none
**Special notes for your reviewer**: This is lint fixes for the Juju python code.
**Release note**:
```release-note
NONE
```
Please consider these changes so we can pass flake8 lint tests in our build process.
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